This chart is based on the
NOAA Geophysical Alert Message (updated every three hours). Included are
the Solar Flux, K-Index, and A-Index numbers for the past six months. This
chart is updated every three hours (at 15 minutes past the hour), along with
the text report at the top of this page.

For more information about these numbers, and what they mean, see the links at
the bottom of this page.